1. Field of the Invention
The present invention relates to an electric contact member, and a developing device, a process cartridge, and an electrophotographic image-forming apparatus, all using the electric contact member.
Hereupon, the electrophotographic image-forming apparatus is an apparatus for forming an image on a recording medium by use of the electrophotographic image-forming process. Then, examples of the electrophotographic image-forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer and the like), a facsimile apparatus, a word processor and the like.
Moreover, the process cartridge is a cartridge into which at least developing means and an electrophotographic photosensitive drum are integrally incorporated, and which is detachably mountable to a main body of an electrophotographic image-forming apparatus.
2. Description of the Related Art
At present, image-forming apparatuses using the electrophotographic image-forming process are widely used. The image-forming apparatus performs image recording through the following processes: a latent image is formed by the light irradiation corresponding to an image signal on an electrophotographic photosensitive member; a developer (hereinafter referred to as toner) is fed to the electrophotographic photosensitive member by the rotation of a developer bearing member; and a developing bias is applied to transfer a toner image on a recording medium.
Such an electrophotographic image-forming apparatus using the electrophotographic image-forming process uses a process cartridge system in which an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally made into a cartridge, which is detachably mountable to the main body of the electrophotographic image-forming apparatus. Because, by the use of the process cartridge system, a user can perform the maintenance of the apparatus in person without relying on a serviceperson, the operating property of the apparatus can remarkably be improved. Accordingly, the process cartridge system is widely employed in electrophotographic image-forming apparatuses.
FIG. 2 is a diagram showing the structures of a developer bearing member (hereinafter referred to as a development sleeve) and a photosensitive drum of a process cartridge. The photosensitive drum 51 is rotatably supported by a frame 59 of the process cartridge. The development sleeve 50 is disposed with a predetermined space from the photosensitive drum 51 with spacer runners 52 and 53 that are fitted onto both of the ends of the development sleeve 50. The development sleeve 50 is composed of a sleeve cylinder 57 of an aluminum pipe, a magnet roller 56 disposed in the sleeve cylinder 57, sleeve flanges 54 and 55 made of resin, a sleeve electrode 58 for applying a developing bias to the development sleeve 50, and the like.
FIG. 3 is a perspective view showing the structures of the sleeve flange 54 and the sleeve electrode 58. The sleeve electrode 58 includes a contact portion 58a conducting electricity to the sleeve cylinder 57, and a contact portion 58b conducting electricity to a developing bias electrode 60 formed on the process cartridge frame 59, to which contact portion 58b a developing bias voltage, from the main body of the electrophotographic image-forming apparatus, is applied. The sleeve electrode 58 is attached to the sleeve flange 54. On the surface of the sleeve flange 54, a groove 54a along the shape of the sleeve electrode 58 is formed. The sleeve flange 54 is force-fitted into the sleeve cylinder 57 with the sleeve electrode 58 fitted into the groove 54a, and the contact portion 58a and the inner peripheral surface of the sleeve cylinder 57 contact each other to conduct electricity therebetween.
The development sleeve 50 constructed in such a way is rotatably attached to the process cartridge frame 59 as shown in FIG. 2, and the sleeve electrode 58 and the developing bias electrode 60 electrically contact each other.
The present invention is one that has further developed the aforesaid conventional art.
One object of the present invention is to provide an electric contact member capable of applying a development bias voltage more surely to a development sleeve, and a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
Another object of the invention is to provide an electric contact member capable of applying a development bias voltage more stably to a development sleeve, and a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
A further object of the invention is to provide an electric contact member for further improving a circularity of a flange, and a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
A still further object of the invention is to provide an electric contact member which can stably perform an electric contact with a frame side electrode, and a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
A still further object of the invention is to provide an electric contact member a part of which is disposed in the inside of a flange, and a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
A still further object of the invention is to provide an electric contact member comprising:
a coil spring portion for being electrically connected with a frame side electrode formed on a frame supporting a development sleeve, the coil spring portion being to be projected from one end portion of the flange when the electric contact member is attached to the flange;
a contact portion for contacting with the inner surface of the development sleeve when the flange, to which the electric contact member is attached, is attached to an end portion of the development sleeve, the contact portion being to be projected from the other end portion of the flange; and
a connecting portion for connecting the coil spring portion and the contact portion, the connecting portion being to be disposed in the inside of the flange when the electric contact member is attached to the flange, and
a developing device, a process cartridge and an electrophotographic image-forming apparatus, all using the electric contact member.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.